1. Field of the Invention
The present invention relates to the field of display techniques, and in particular to a structure of gate on array (GOA) circuit.
2. The Related Arts
The liquid crystal display (LCD) provides many advantages, such as thinness, low power-consumption and no radiation, and is widely used in, such as, LCD televisions, mobile phones, personal digital assistants (PDAs), digital cameras, computer screens, laptop screens, and so on. The LCD also dominates the field of panel displays.
Most of the LCDs on the current market are of backlight type, which comprises an LCD panel and a backlight module. The operation theory behind LCD is to inject the liquid crystal (LC) molecules between a thin film transistor (TFT) array substrate and a color filter (CF) substrate, and applies a driving voltage between the two substrates to control the rotation direction of the LC molecules to refract the light from the backlight module to generate the display on the screen.
The active matrix liquid crystal display (AMLCD) is the most commonly used liquid crystal display, which comprises a plurality of pixels, each pixel is controlled by a TFT, the gate of the TFT is connected to a scan line in a horizontal direction, the drain is connected to a data line in a vertical direction, and the source is connected to a corresponding pixel electrode. When a sufficient positive voltage is applied to a scan line in the horizontal direction, all of the TFTs connected to the scan line are turned on, the data signal voltage loaded on the data line is written into the pixel electrode to control the transmittance of different liquid crystals to achieve the effect of color control.
The driving of the horizontal scan line (i.e., gate driving) of the AMLCD horizontal is initially executed by an external integrated circuit (IC). The external IC can control the charge and discharge of the horizontal scan line in each stage progressively. The gate driver on array (GOA) technology, i.e., the array substrate column driving technology, can use the array process of the LCD panel to manufacture the driver circuit of the horizontal scan lines on the substrate at area surrounding the active area to replace the external IC for driving the horizontal scan lines. The GOA technology can reduce the bonding process for external IC and has the opportunity to enhance yield rate and reduce production cost, as well as make the LCD panel more suitable for the production of narrow border display products.
As the display technology progresses, the resolution of the display is also higher and higher. For the displays of the same size, the higher the resolution of the display, the high the number of the stages of GOA circuit is required, and more routing area is occupied, which needs wider display panel border, and is not suitable for the realization of ultra-narrow border or borderless display panel. As a result, the GOA circuit lost the advantages in the production of narrow border display product.